Cooled converter trunnion ring

ABSTRACT

A cooled converter trunnion ring, which is arranged at a distance from the converter, encompasses the converter and is connected to a coolant supply station. In order to achieve good accessibility of the trunnion ring by simple measures and to ensure reliable cooling of the loaded trunnion ring areas with low energy expenditure, a pipe coil, which runs in a largely meandering fashion and through which a liquid coolant flows, is provided on the inner surface of the inner side member substantially facing the converter of the steel mantle of the converter trunnion ring.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a cooled trunnion ring for a converter, andmore particularly to a trunnion ring that is arranged at a distance fromthe converter, encompasses the converter and is connected to a coolantsupply station.

2. Description of the Prior Art

Converters used in steel production, when of a certain size or larger,are located in non-attached trunnion rings. When an increased demand isplaced on converter vessel capacity, especially when refractory liningswith high carbon content are used, the thermal load of the converterwall, like that of the trunnion ring, becomes ever greater. This thermalload also effects the trunnion ring arranged at a distance ofapproximately 100 to 200 mm from the converter.

In order to prevent the permissible limits for the vessel mantle frombeing exceeded and, at the same time, to reduce the thermal load of theconverter trunnion ring, a cooling medium is customarily conducted inthe space between the ring and the vessel mantle. Thus, an air coolingsystem for heatable metallurgical vessels equipped with non-attachedtrunnion rings is known from DE 39 27 928 A1. In this system, air ductsare arranged on the outer side of the trunnion ring, via which coolingair is conducted between the trunnion ring and the outer wall of themetallurgical vessel. The disadvantage of this air cooling system isthat gaseous media have only a low capacity for extracting heat.Additionally, the air in this system is blown off, which is undesirablefor environmental reasons.

It is also known to completely fill the trunnion ring with water forcooling purposes. Disadvantageously, the water supplied and extractedthrough the trunnion increases the weight of the trunnion ring.Furthermore, in the event of certain malfunctions, for example, a vesselbreak-out, the trunnion ring may also suffer damage, resulting in adangerous convergence below the converter of liquid melt anduncontrollable quantities of water. Moreover, when high thermal loadsare placed on the trunnion ring mantle, especially given the low flowspeed of the cooling water, blistering occurs on the inner wall (theso-called "killing frost effect"). The negative consequence of this isthat heat extraction is prevented at these locations.

In addition, filling the interior of the converter trunnion ring withwater makes it inaccessible for the purpose of inspection andmaintenance.

SUMMARY OF THE INVENTION

Accordingly, it is an object of the present invention to provide acooling system for a converter trunnion ring which, via simple means,permits the trunnion ring to be freely accessible and ensures reliablecooling of the loaded trunnion ring areas at a low expenditure ofenergy. Pursuant to this object, and others which will become apparenthereafter, one aspect of the present invention resides in a cooledconverter trunnion ring that can be arranged at a distance from theconverter and encompasses the converter. The trunnion ring is comprisedof a steel mantle having an inner side that faces the converter, whichinner side has an inner surface to which a pipe coil is mounted in ameandering fashion. A liquid coolant flows through the pipe coil toprovide cooling.

According to the invention, a tubular coolant conduit, which runs in alargely meandering fashion, is provided on the mantle of the convertertrunnion ring. Portions of the coolant conduit--for example, at openingsthrough the transverse metal sheet--may be formed by pipes that runparallel to one another. Cooling water is conducted through this pipecoil in a relatively low quantity but at relatively high speed. The pipecoil is arranged in such a manner that the individual parallel sectionsof pipe are spaced at a distance from one another equal to at leasttwice their diameter (in reference to the center line), so that broadportions of the trunnion ring mantle are cooled by a single coolingline, starting from the cooling line and moving outward, without cominginto contact with the coolant. The advantage here is that the requiredquantity of coolant is reduced while the flow speed is increased. Inaddition, areas are left free to allow inspection of the trunnion ringmantle, e.g., for cracks, etc. Moveover, during extreme emergencies,e.g., in the event of local destruction of the trunnion ring, thecoolant supply can be shut off within a short time without largerquantities of water continuing to flow.

According to a further embodiment of the invention a part of thetrunnion ring mantle is incorporated into the cooling system. For thispurpose, pipe sections such as half-pipes, angle sections and U-sectionscan be used. These can be intimately connected to the trunnion ringmantle by means of single welded seams.

In a further embodiment of the invention, a cooling block is used, whichconsists, for example, of aluminum and has interconnected bores. Thisblock is pressed by a contact mass against the inner surface of thetrunnion ring. In still another embodiment the coolant conduits aredivided into separate cooling circuits and these be connected to acontrol device. This permits energy consumption to be reduced evenfurther, because cooling can be initiated by the control device in amaimer adjusted to the load.

The various features of novelty which characterize the invention arepointed out with particularity in the claims annexed to and forming apart of the disclosure. For a better understanding of the invention, itsoperating advantages, and specific objects attained by its use,reference should be had to the drawing and descriptive matter in whichthere are illustrated and described preferred embodiments of theinvention.

BRIEF DESCRIPTION OF THE INVENTION

FIG. 1 is a section through the converter trunnion ring pursuant to thepresent invention;

FIGS. 21, 2b, 2c, 2d and 2e illustrate embodiments of the pipe coil;

FIG. 3 shows a measurement and control device of the cooling waterconduit; and

FIG. 4 is a section of FIG. 3.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1 shows, in section, a converter 10 with a converter mantle 11 anda refractory lining 12. A converter trunnion ring 20 is arranged at adistance from the converter 10. The trunnion ring 20 has a mantle 21 towhich partitions 26 are connected. The mantle 21 includes an inner sidemember 24, an upper member 23 and a lower member 25. A pipe coil 31 isprovided on the inner surface 22 of the upper member 23, the lowermember 25, and the inner side member 24 of the trunnion ring mantle 21facing the converter 10.

FIGS. 2a-e show various design forms of the pipe coil 31, designed asthe pipe section 32 and located, in the examples, on the inner sidemember 24 of the trunnion ring mantle 21. In FIG. 2a, the pipe section32 has a square cross-section 33, which is welded onto the inner sidemember 24 and is connected to the latter, with respect to heat flow, viaa contact mass 41, such as a paste having a high conductivity.

In FIGS. 2b, 2c and 2d, an angle section 34, a half-pipe 35 and aU-section 36 are respectively shown, whereby the respective free ends ofthe sections are connected to the inner side 24 and form with the latterthe pipe section 32. The center axis of the pipe section is indicatedwith the letter I. The portion of the inner surface 22 that forms partof the pipe cross-section is less than half the total inner surface ofthe pipe section 32.

The example shown in FIG. 2e is an aluminum cooling block 37, providedwith the bores 38. The block 37 is connected via the contact mass 41 tothe inner side member 24 of the trunnion ring mantle 21.

FIG. 3 shows a longitudinal section through the upper member 23 and thelower member 25, as well as the partitions 26 of the trunnion ring 20.The meandering course of the pipe coil 31 can be seen in this Figure.Specifically, a coolant conduit 30 is shown with an essentially verticalflow direction cooling circuit K1 on the left side and an essentiallyhorizontal cooling circuit K2 on the right side of the coolant conduit30. The cooling circuits K1 and K2 are connected to a control loop 50which includes control and regulating device 54, which has a safetyvalve 51, a pressure control device 52 and a temperature sensor 53. FIG.4 is a section through the vertical cooling circuit K1 for comparison tothe section through circuit K2 shown in FIG. 1.

The inner surface 22 of the trunnion ring 20 which forms the common wallof the pipe coil 31 forms a portion of the cross-section of the pipesection 32 based upon the following relationship: UT<0.7 UR, where UT isthe portion of the cross-section formed by the trunnion ring innersurface 22 and UR is the remaining portion of the pipe section 22.

The invention is not limited by the embodiments described above whichare presented as examples only but can be modified in various wayswithin the scope of protection defined by the appended patent claims.

I claim:
 1. A cooled converter trunnion ring arrangeable at a distancefrom a converter so as to encompass the converter, the trunnion ringcomprising: a steel mantle having an inner side arrangeable tosubstantially face the converter, the inner side having an innersurface; and at least two pipe coils mounted on the inner surface of theinner side of the steel mantle in a meandering fashion so that a portionof the inner surface of the steel mantle forms part of the pipe coils,as seen in cross-section, and so as to permit a liquid coolant to flowthrough the pipe coils, the pipe coils being arranged so that adjacentpipe coils are separated by a distance that is at least twice a diameterof the pipe coils.
 2. A cooled converter trunnion ring as defined inclaim 1, wherein the portion of the inner surface of the steel mantlewhich forms the part of the pipe coil cross-section is less than half ofthe entire inner surface, a remaining portion of the pipe cross-sectionbeing one of an angle, a half-pipe and a U-section.
 3. A cooledconverter trunnion ring as defined in claim 1, wherein the portion ofthe inner surface of the mantle which forms part of the pipe coil formsa portion of the cross-section of the pipe coil based upon therelationship UT<0.7 UR, wherein UT is an amount of the cross-sectionformed by the inner surface and UR is a remaining portion of thecross-section.
 4. A cooled converter trunnion ring as defined in claim1, and further comprising a cooling block having bores therein whichform the pipe coil, and a contact mass provided so as to connect thecooling block to the inner surface of the mantle in a total areafashion.
 5. A cooled converter trunnion ring as defined in claim 4,wherein the cooling block is made of aluminum.
 6. A cooled convertertrunnion ring as defined in claim 4, wherein the contact mass is a pastehaving high conductivity.
 7. A cooled converter trunnion ring as definedin claim 1, wherein the pipe coil forms a coolant conduit which isdivided into separate cooling circuits.
 8. A cooled converter trunnionring as defined in claim 7, and further comprising a control loop whichincludes safety valves, pressure control devices and temperature sensorsoperatively connected to the separate cooling circuit to monitor andcontrol coolant quantity in the cooling circuits.
 9. A cooled convertertrunnion ring as defined in claim 1, and further comprising coolantsupply means for supplying coolant to the pipe coil.